Note: you have two 2's.

I didn't go to grad school.

1. I didn't go for a few reasons. First, I would have to pay for it which sounded lame. Second, a lot of my friends were going because they didn't know what to do next and school was an easy path to keep following. That seemed like a bad reason, so I opted out.

2a. When didn't I go? In the past. I'm still open to the idea of going in the future, and there might be a time when that higher education is the best path for progression for my current career path. Or, it'll be the best way for me to shift my career path. My mom got her master's in her mid 40's and changed her work, so I know that's a viable path.

2b. If you want to go to a profession that requires higher education. I have friends who are engineers and they just have to go to grad school to be competitive. I have friends who want to be managers and they went back to grad school after a few years in the workforce to give them a foot into middle management. It's mostly been a good decision when you know what you want to do with the certification you'll be coming out with. Also, you have to understand that this fancy and expensive certification does not guarantee anything. You are not promised a job, which is another reason you really want to know what you want to do, you might have to fight to find something while debt breaths down your neck.

3. I touched on my opinion of this in question 1, but the broader answer is "when you don't know how the investment will pay off." I went into the workforce with the mindset that my first two years were going to be my graduate studies. I took a shit job in the "mail room" of a company, and didn't really worry about looking good or not drawing attention, because this was just a two year program. With that mindset I was able to learn how to fight my way out of entry level and into the work that satisfied me. I got paid for that education while having friends who were paying for a less practical application.

4. I haven't been in grad school but, for me, the best way to approach a long term project is to have a vision of what you want at the end of your journey. Make sure it's tangible enough to provide clear motivation, but malleable enough to evolve as you learn.

5. What are you actually learning? Are they practical skills in a practical environment, practical skills in a theoretical environment, theoretical skills in a theoretical environment, theoretical skills in a practical environment? In which of those situations do you learn best? What do you want to explore, build, or study?

6. I drove a taxi in undergrad. Might not be as profitable now that Uber's out there, but drunk people tip well if you're fun enough, and if you can buckle down and commit to work during key party nights you can make very, very good money with about 12 hours work per week.

Otherwise, what can you do well? What skills are you looking to build on in grad school? Can you figure out how to use those foundational skills to generate income? If the answer to that is "no" you might want to find an answer to that question before anchoring your foreseeable career future to that profession.

Good luck!